Alert archive / New Jersey / Flash Flood Warnings in 2024

Flash Flood Warning 22, NWS Philadelphia/Mount Holly

July 21, 2024Burlington County, New Jersey; Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 21, 2024, 7:59 PM EDT for Burlington County, New Jersey; Philadelphia County, Pennsylvania. It was in force for 112 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 21, 2024, 7:59 PM EDT (23:59 UTC)
Expired
Jul 21, 2024, 9:51 PM EDT
In force
112 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Burlington County, NJ, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 53 km from the middle of the area, began a volume at 00:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 12.0 hours before the alert went out and 204 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2024-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2024-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1500 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

210 
WGUS51 KPHI 212359
FFWPHI
NJC005-PAC101-220400-
/O.NEW.KPHI.FF.W.0022.240721T2359Z-240722T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
759 PM EDT Sun Jul 21 2024

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  West Central Burlington County in southern New Jersey...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until midnight EDT tonight.

* At 759 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 2 inches are possible in 
  the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets, and underpasses as well as other
           drainage and low lying areas.

* Some locations that may experience flash flooding include...
  Philadelphia, Riverside, Palmyra, Holmesburg, Tacony, Wissinoming, 
  Cinnaminson, Riverton and Moorestown-Lenola.

This includes the following highways...
	Interstate 295 in New Jersey between mile markers 40 and 45.
	Interstate 95 in Pennsylvania between mile markers 28 and 33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4005 7510 4006 7510 4006 7509 4009 7506
      4006 7498 4005 7498 4005 7497 4001 7484
      3995 7490 4003 7512

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

RCM
1 follow-up statement
623 
WGUS71 KPHI 220151
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
951 PM EDT Sun Jul 21 2024

NJC005-PAC101-220201-
/O.CAN.KPHI.FF.W.0022.000000T0000Z-240722T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Philadelphia PA-
951 PM EDT Sun Jul 21 2024

...FLASH FLOOD WARNING IS CANCELLED FOR WEST CENTRAL BURLINGTON AND 
NORTHEASTERN PHILADELPHIA COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

&&

LAT...LON 4005 7510 4006 7510 4006 7509 4009 7506
      4006 7498 4005 7498 4005 7497 4001 7484
      3995 7490 4003 7512

$$

RCM

Nearby

Flash Flood Warnings in New Jersey, 2024Flash Flood Warnings in Pennsylvania, 2024Every flash flood warning in 2024

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.